More doc fixes [PATCH]

[Antoni Bella Pérez]

El dijous, 7 de desembre de 2017, a les 8:49:52 CET, Gilles Caulier va 
escriure:
> Hi,
> 
> The handbook do not build with the patch. See the trace below :
> 
> Generating index.cache.bz2
> using-mainwindow-albumsview.docbook:70: parser error : Entity 'Return' not
> defined
>  on an Album and select <guilabel>Properties</guilabel>
> (<keycombo>&Alt;&Return;

  Hi,

  Change &Return; entity to &Enter;

  Regards
  Toni